This invention relates generally to inflatable air cell systems for occupant support in seating and mattress applications and, more particularly, to the provision of an expandable chamber that includes a wall segment formed of conductive material dispersed in polymeric material and operable to heat seating or mattress applications.
Fluid expandable chambers such as expandable chamber or air cells, particularly for pneumatically adjustable occupant support systems in seating or other support applications, are frequently constructed from facing layers of a flexible, air-impermeable material such as thermoplastic urethane, fabric reinforced polyvinylchloride, and other plastic film materials, that are dielectrically sealed or otherwise joined about their marginal edges to enclose an interior inflatable air chamber. A tube connected to such expandable chamber is coupled to a fluid control system for inflation and deflation of the expandable chamber.
Traditionally, such expandable chambers are inflated by either pressurizing or deflating one or more of the cells in accordance with a predetermined control algorithm for providing a desired user support. Alternatively, the pressure can be controlled by a pump and switch under the control of any controller including a timer, a microcomputer or any other form of computer. In such arrangements, the individual expandable chamber or air cell have been located in desired seating configurations including the lumbar region and ischial regions of a user. In such seats a further practice has been to perforate an overlying trim material so that the seat cushion or seat back support surfaces will tend to breath. Leather or a suitable plastic material such as PVC, urethane, polyolefins or the like materials have been provided to give a level of so called breathability.
While suitable for their intended purpose such arrangements neither cool or heat a seat to meet desired uniform thermal comfort considerations. Other seating arrangements are known that will heat or cool a seat. Examples of such arrangements are set-forth in the following listed patents.
It is also known to provide conductive extrudate articles configured with flat surfaces that will radiate heat when the articles are connected across an electrical source. Examples of such articles are set-forth in U.S. Pat. Nos. 4,954,695 and 5,181,006.
None of the aforesaid arrangements, however, provide for heating a support surface by use of a self heating expandable chamber such as an expandable chamber or air cell.
The present invention is directed to a fluid support arrangement wherein the fluid inflatable bladder or air cell itself alone provides both thermal conditioning and a containment for a pressure medium for providing desired occupant support. Furthermore, the invention avoids the need for installation of separate heaters within the confines of seating and other types of occupant supports that embody such fluid inflatable bladders or air cells.
The invention for occupant support such as vehicle seating and mattress applications includes an expandable chamber such as an inflatable pressure adjustable air cell or bladder constructed from facing sheets of flexible, air-impermeable cell material sealed along adjoining marginal edges thereon. The facing sheets are comprised of conductive material dispersed as discrete particles embedded in polymeric material to define a self heating sheet that will produce electrical resistance heating of the surface for thermally conditioning the body contacting surface of a vehicle seat or other occupant support application while retaining pressurized fluid within the expandable chamber.
The expandable chamber conforms to an occupant supported thereon and the provision of the self heating sheet therein combines a pressure adjusted shape for support and heating.
A feature of the invention is to provide combined pressure and thermal heating functions in an expandable chamber comprised of two layers of material wherein at least one of the layers is polymeric material having conductive material formed as discrete particles embedded therein that will produce electrical resistance heating for thermally conditioning a body contacting surface of a vehicle seat, furniture seating, mattress or other occupant support application.
A further feature is to provide an expandable chamber such as an inflatable bladder or air cell; the expandable chamber having imperforate walls for containing pressure and a supply tube connected to a fluid system for controlling the pressure in the expandable chamber for providing occupant support and wherein one imperforate wall of the expandable chamber is comprised of a conductive material dispersed in a polymeric material to heat the supported occupant and wherein another imperforate wall of the expandable chamber is formed from electrically insulated, non conductive material and joined to the one imperforate wall to contain pressure within the expandable chamber.
A further feature is to provide such combined pressure support and heating in an expandable chamber including two sealed layers having electrical power leads formed thereon for directing electricity through a top layer formed of electrically conductive carbon loaded polymeric material.
A still further feature is to provide such pressure support and heating in a fluid support system wherein preselected expandable chambers are associated with at least one imperforate support surface formed as a layer of electrically conductive carbon loaded polymeric material that will conform to a supported occupant and when connected across a power source will provide heating.